A problem while working with 2D graphics, in the style of big concept maps or other kind of diagrams, is that when the matter is complex, they can become a problem to navigate and edit them like in the next very cluttered map:

This is unavoidable if you need to show (or print) the map as single unit.

However, with the help of software, you can divide the map in hierarchically contained sub-maps, spanning multiple levels. Consider the next diagram, made with ThinkComposer, representing a simple aircraft design as an advanced concept map:

With this multilevel capability you can “compose” (or decompose) your ideas to any extent into a single document. Plus, notice that you can still connect nodes, not within the same view (map/diagram), by using Shortcuts that you can point/click to easily navigate to the original source.

Sequence diagrams: Represents the behavior of related components on the execution of a system (or subsystem). It shows the invocations, returns, paralellization, starts and stops of those participants.

Visual Languages for Specialized contexts…

Electronic Diagrams: Shows electronic components and their arrange on a circuit or board.

Military Plan: Shows the planification for war movements. It considers direction, timing, type and strength of forces in the theater of operations.

Maybe, for any human knowledge area, there are a visual language developed. Plus consider that many organizations have developed their own visual languages, and they are changing over time and evolve following the development on their industries or even creating new ones (e.g.: nanotech, genetic engineering). Such particular well focused dialects are called Domain Specific Languages.